Generally, the presence of bulk materials in a heterogeneous waste mixture prevents treatability of the waste stream by any single, established technology. Current storage and disposal methods are both costly and in violation of laws governing the storage of mixed waste.
In previous practices, some facilities have generated large quantities of wastes which contain both a hazardous chemical component or components and a radioactive component. This type of waste is referred to as a mixed waste. Mixed wastes are still generated by some facilities, e.g., those involved in activities such as decontamination and decommissioning of actinide processing operations. One class of mixed wastes is generated when paint is stripped from surfaces contaminated with an actinide such as plutonium. Such a waste typically includes a paint stripper such as methylene chloride together with other solvents, lead- and cellulose-based paint, bulk materials such as cheesecloth rags, cardboard and cotton labcoats, and in some cases, minor amounts of a radioactive component such as plutonium. As current storage practices are expensive, if not unlawful under U.S. laws, and alternatives such as incineration have not gained general acceptance, the development of an environmentally benign, publicly acceptable solution has been sought.
An object of the present invention is a process for treating heterogeneous wastes such as mixed wastes whereby organic components such as volatile organic components and other hydrocarbons are removed or eliminated, contaminant toxic metals such as lead, chromium and the like are separated, and the volume of any bulk materials is reduced.